Thursday, May 26, 2011

Re_home designed to provide more than shelter in wake of disaster

Re_home designed to provide more than shelter in wake of disaster

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Just as the dust settled from the departure of students last week, there was an exciting and much anticipated arrival on the University of Illinois campus. On Tuesday morning, the shell for the University’s entry in this year’s Solar Decathlon was delivered to a site near the ACES Library.

The Solar Decathlon, you may remember, is a biannual competition among entrants from 20 universities from around the world, sponsored by the U. S. Department of Energy. The competing teams, which are selected from a much larger pool based on the quality of their initial proposals, strive “to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive.”

The structure delivered last Tuesday will become the third entry in the competition for the U of I, which captured 2nd place overall in 2009, after placing 9th with its first entry in 2007.

For this year’s model, the U of I team adopted the task of creating a home that would be useful in the wake of a natural disaster, so it is designed for rapid assembly as well as sustainability. The home’s two modules are sized for easy transport by truck, and the structure will incorporate extra outdoor space by means of decks and awnings. In the words of Mark Taylor, one of the faculty members who guides the project, “We wanted to create a house with large, open spaces, a place where people can come together and look ahead, not simply a shelter for them to retreat to.”

On the inside, the home will provide about 900 square feet of living space. It will be ADA-compliant, with wide doorways, level thresholds and space in the bathroom to turn a wheelchair around. The windows will be oriented to take full advantage of the sun for lighting year round, and for passive heating in the winter. Of course, the materials used to finish the home were selected with sustainability in mind.

“Net-zero” energy use is a must for entries in the solar decathlon, so the engineering students who participated in the design of the home were charged with ensuring it will use no more power than the solar panels on its roof produce. It will require only minimal heating and cooling, thanks to meticulous weather sealing, super insulated walls and triple-pane glass. What heating and cooling are needed will be provided by an intelligent, nimble system developed especially for ultra efficient homes by Newell Instruments in Urbana. The electrical appliances to be used in the home were chosen for their efficiency, but all of them are also affordable, off-the-shelf products.

The shell of the home that was delivered last week was constructed by a commercial maker of modular buildings, Homeway Homes of Bloomington, Illinois, according to designs developed by U of I students. In a nutshell, Homeway’s part was to put together the insulated stud framing, install the windows and doors and put in the subfloor.

Over the course of the summer, U of I students from architecture and engineering will complete the construction. They will install insulated panels to finish the exterior walls, assemble the photovoltaic array on the roof, build the exterior decking, put down flooring inside, and more.

Come September, the home will be trucked to the National Mall in Washington D. C., where the U of I team hopes to unseat two-time reigning champions, Team Germany.

You can learn more and follow progress on the Re_home at

Friday, May 20, 2011

How life copes with floods in streams and floodplains

How life copes with floods in streams and floodplains

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[Please note: this piece ran originally on June, 12, 2008, when flooding was more severe in the Midwest, but we pulled it out as an archive spot for the radio in light of this year's flooding in the South.]

This spring’s heavy rains in the Midwest have resulted in all manner of difficulties for people, from the tragedy of lost lives to the pain and hardship of flooded homes and farm fields. This is where humans need to come together and help one another out.

The other forms of life that inhabit streams and stream corridors are also coping with the high waters, some more easily than others.

At the bottom of freshwater streams, unusually strong flows may deposit large amounts of sediment on top of mussels, which live hunkered down in sand and gravel. Mussels cannot survive if they stay buried completely, so they must make their way up to the new surface of the streambed in order to survive. Where the streambed is scoured away in flooding, some light-shelled mussel species may be swept up in the current, and then left high and dry when floodwaters recede. After the Mississippi River flood of 1993, scientists from the Illinois Natural History Survey found stranded mussels at densities of up to 1 per meter in farm fields more than a mile from the river. Individual mussels stranded on dry land can’t survive, but the problem of stranding doesn’t seem to have a long-term impact on the overall health of mussel populations

Creatures that live on and near the streambed--including crayfish, insect larvae, and other invertebrates--need access to stable refuges in order to ride out flood pulses. Such refuges may include rocks or logs that remain in place, as well as undercut banks and other streambed irregularities that create pockets of reduced current.

Farther up in the water column, fish use their mobility to cope with rising waters, and they even benefit from floods in some circumstances. Fish may ride out a short-term flood by seeking pockets of water that are protected from strong currents, or moving up into smaller tributary streams. In more extensive, long term floods fish take advantage of the opportunity to move out into areas that are not normally submerged. Slow moving water on a floodplain quickly becomes rich in microscopic life, which attracts minnows and other small fish. And where small fish go, the larger fish that feed on them follow. The rich soup of flood waters also offers a variety of seeds from trees and other plants, as well as drowned insects, and more. If water persists in the floodplain long enough, some fish will even take advantage of the opportunity to spawn there.

The trees common to floodplains are also adapted to occasional high water in fascinating ways. Willows, for example, are extremely flexible, so that they bend in strong currents rather than breaking. A willow that’s bent over far enough to be buried with sediment can even send up branches that then emerge from the ground like new trees. So when you see a straight line of little willows on a gravel bar, you may actually be looking at shoots coming up from the trunk of a tree laid down by a flood.

While flooding in the Midwest was once an entirely natural occurrence, it isn’t anymore. Our streams now rise higher and faster than they used to because we are so good at moving rainwater off of the land quickly, with drainage for agriculture and paving and building in cities and suburbs. The real challenge to us now is developing landscapes that will once again hold some water back.

Thursday, May 12, 2011

Emergence of the “Great Southern Brood” coming to Illinois

Emergence of the “Great Southern Brood” coming to Illinois

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Whether you anticipate it with pleasure or dread, there’s a large-scale natural phenomenon headed our way in the weeks to come, an emergence of 13-year periodical cicadas.

The insects in question are part of a group designated Brood XIX (19), or “The Great Southern Brood.” It occurs over a greater geographical range than any of the other 13- or 17-year cicada broods, with activity in 14 states anticipated. Like other year-classes of periodical cicadas, which, for the record, occur only in eastern North America, Brood XIX is composed of individuals representing three or four closely related cicada species.

Individuals from Brood XIX first began emerging in South Carolina in the third week of April, and they have now been reported aboveground in at least eight other states across the South and as far west as Oklahoma. The emergence of periodical cicadas seems to depend on soil temperatures reaching 64 ˚F, so it progresses from south to north with the season.

The current generation of the Great Southern Brood hatched from eggs laid in tree branches in the summer of 1998. As tiny nymphs, no bigger than small ants, they dropped to the ground and burrowed in. There they have been feeding on tree roots, and undergoing a five-stage development in anticipation of their turn at life on the wing. When the time is right, they will travel to the surface by way of a self-excavated tunnel and crawl up a tree, or whatever other vertical object happens to be nearby. There they will shed a nymphal skin one last time. [Photo: An adult periodical cicada newly emerged from its nymphal shell. John H. Ghent, USDA Forest Service,]

Periodical cicadas live as adults for only a few weeks, during which time they are interested in two things: feeding and reproduction.

Cicadas feed on the watery part of plant sap from trees and shrubs, which they extract by means of piercing-sucking mouth parts. Their feeding does not normally damage plants, since they remove only very small quantities of fluid and they do no significant damage to get at it. Since cicada mouths are designed to extract liquid from plants, you can rest assured they won’t bite people or other animals.

Of course, people and other animals will bite cicadas. The long list of creatures that eats them includes spiders, snakes, birds, dogs and more. If you stop to think about it, what small- to medium-sized animal that’s not strictly a plant eater would pass up such a bounty? As for people eating periodical cicadas, well. Historically, some groups of American Indians are reported to have eaten them (I haven’t been able to find whether they still do), and every emergence brings out recipes for them in newspapers and on the Web. I’ve never tried them, but I have to admit I’m intrigued—maybe this year.

Whether I eat them, you eat them or we and all the other predators eat them, enormous numbers from this year’s Brood XIX emergence will survive to accomplish the primary task of adult cicadas, reproduction. (And that’s precisely the point of their highly synchronized life cycle; scientists call it “predator satiation.”)

The males will entice mates with their long, loud song, often singing together in great congregations for an amplified effect. The females, once they have mated, will create a small slit in a branch, where they will lay their eggs, 400 to 600 of them. Egg-laying is really the only aspect of cicada behavior people might want to take precautions against, and only where cicadas turn out to be concentrated, since very young trees and shrubs may not tolerate the damage to small branches it involves. In such cases, cloth netting can be used to exclude cicadas.

Otherwise, the emergence of Brood XIX should be a great occasion for engaging the weird beauty of the life that surrounds us.

For more about Brood XIX and other periodical cicadas, check out

Thursday, May 05, 2011

Let spring migration awaken your inner birder

Let spring migration awaken your inner birder

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The weather last Wednesday morning argued against outdoor activity, with heavy clouds threatening to unleash a downpour at any moment. But Wednesday morning was the time a birding jaunt best fit among the other demands of the week, so that’s when I went. I set out with some hope, too, because I’ve found that opportunities sometimes open up even when the forecast is dire; it seldom actually rains all day, right? Plus, migrating birds often travel with weather fronts, so people who are willing to cope with a little rain are usually the first to see what has blown in with a storm.

I headed for Crystal Lake Park in Urbana, which is for local birders the place to be at this time of year, when songbird migration is kicking into high gear. There’s a special combination of habitat components there—ancient oaks, open space, water with brushy margins—that attracts remarkable concentrations of birds.

I saw no other birders when I arrived at the Lake House, but a car belonging to my friend, Greg Lambeth, was there. Greg is a clinical psychologist at the UI and a passionate birder, who makes time to get out for a couple of hours before work whenever possible at this time of year.

A light rain was falling--enough to make rain pants worth the effort, but not to make me leave my camera behind. Even as I pulled myself together, I was energized by sounds from the branches above, the quiet “chips” of yellow-rumped warblers and the buzzy calls of blue-gray gnatcatchers.

I caught up with Greg as he scanned a flock of warblers flitting among the trees along the Saline Branch, the stream that runs through the park. He pointed out that the flock extended some distance upstream and downstream from where we stood, as well as into the woods on the other side. I was stunned by the abundance. There were so many birds bouncing around it was difficult to keep track of which we had identified and which we hadn’t. [Upper photo of prothonotary warbler by author; lower of scarlet tanager by Greg Lambeth.]

The greatest numbers of them by far were yellow-rumped warblers, which, as you might expect, are named for the colorful patch above their tail. But we spotted 12 other species of warblers that morning, too, among them my favorite, a prothonotary warbler. This is a bird whose yellow head and chest are so bright he appears to be lit from within.

And warblers were only one part of the picture on Wednesday. were scarlet tanagers, whose brilliant red body feathers are accented by jet-black of wings, and Baltimore orioles, whose striking combination of orange and black may be more familiar to you. There were indigo buntings, there were two kinds of vireos, there were . . . well, more birds than you would probably care to hear me describe.

So take this as encouragement to get out and see spring migration for yourself. A great place to start is with the Champaign County Audubon Society’s weekly bird walks, which Greg Lambeth usually leads. Novices and experienced birders alike are welcome at these walks, which set out from the Urbana Park District’s Anita Purves Nature Center at 7:30 on Sunday mornings through the month of May.

See more bird photographs by Greg Lambeth, many from Crystal Lake Park and Busey Woods at

Further details about Sunday morning bird walks at